Quantitative Analysis of the Benefits and Risks of Consuming Farmed and Wild Salmon

Title: Quantitative Analysis of the Benefits and Risks of Consuming Farmed and Wild Salmon

Journal Source: The Journal of Nutrition

Link: http://jn.nutrition.org/content/135/11/2639.long

Summary: This study looked at the relative risks of exposure to contaminants in both farm raised Atlantic salmon (from North America, South America, and Europe) and wild Pacific salmon. Types of contamination were categorized into two groups- carcinogenic (cancer causing) and non-carcinogenic. The most common contaminants are dioxins, polychlorinated biphenyls (PCB), polybrominated diphenyl ethers, and some pesticides. The study measured these risks using the Benefit Carcinogenic Risk Ratio (BCRR) and the Benefit Non-Carcinogenic Risk Ratio (BNRR)- that is, the relative heath benefits of consuming EPA and DHA from the fish vs. consequences of consuming too many contaminants.

They found that although on average farmed salmon have "significantly higher" concentrations of omega-3s than wild salmon, they also have the tendency to be more contaminated. In terms of non-carcinogenic risk, wild salmon have a higher amount of EPA+DHA per unit of non-carcinogenic risk. Farmed Salmon from Chile and Washington State are almost on par with wild salmon. Conversely, farmed salmon sold in europe have the least amount of EPA+DHA per unit of non-carcinogenic risk. However, both farmed and wild salmon can be consumed at the daily recommended dose of 1 g/day EPA+DHA and stay under acceptable non-carcinogenic risk levels.

The story is different when it comes to carcinogenic risk, however, Neither farmed nor wild salmon can be consumed at the rate of 1 gram/day of EPA+DHA and stay under acceptable risk levels for cancer. Cumulative cancer risk for farmed salmon is 24x acceptable cancer risk level- for wild salmon, it is 8x.

The effects of PCBs, dioxins, and other contaminants in wild salmon can cause neurological complications that are oftentimes irreversible. However, even though this information seems bleak, it is estimated that if half of CHD deaths are prevented by regularly consuming the recommended dose of daily fatty acids (7100 out of ever 100,000 individuals) and an extra 24 deaths per 100,000 individuals die from cancer as a result of consuming fish, the number of lives saved is 300x the number of lives lost when farmed salmon are eaten at a rate of 1 g/d of EPA+DHA.